"""基础测试模块。

测试业务逻辑层 (TodoService) 和 API 层 (FastAPI 路由) 的核心功能。
"""

import pytest
from httpx import AsyncClient, ASGITransport

from app.main import app
from app.services import TodoService
from app.models import TodoCreate, TodoUpdate


# ============================================================
# 单元测试 — TodoService 业务逻辑
# ============================================================

class TestTodoService:
    """TodoService 的单元测试。"""

    @pytest.fixture
    def service(self):
        """每个测试使用全新的 TodoService 实例。"""
        return TodoService()

    def test_create_todo(self, service):
        """测试创建任务：应返回带 ID 和默认字段的有效任务。"""
        data = TodoCreate(title="测试任务", description="测试描述")
        item = service.create_todo(data)
        assert item.id == 1
        assert item.title == "测试任务"
        assert item.description == "测试描述"
        assert item.completed is False

    def test_list_todos_empty(self, service):
        """测试空列表：新建服务应返回空列表。"""
        items, total = service.list_todos()
        assert items == []
        assert total == 0

    def test_list_todos_with_data(self, service):
        """测试列表：创建多个任务后应能正确返回。"""
        service.create_todo(TodoCreate(title="任务1"))
        service.create_todo(TodoCreate(title="任务2"))
        items, total = service.list_todos()
        assert total == 2
        assert len(items) == 2

    def test_get_todo_by_id(self, service):
        """测试根据 ID 获取任务。"""
        created = service.create_todo(TodoCreate(title="查找测试"))
        fetched = service.get_todo(created.id)
        assert fetched is not None
        assert fetched.title == "查找测试"

    def test_get_todo_not_found(self, service):
        """测试获取不存在的任务应返回 None。"""
        assert service.get_todo(999) is None

    def test_update_todo(self, service):
        """测试更新任务：应正确修改标题和完成状态。"""
        created = service.create_todo(TodoCreate(title="原标题"))
        updated = service.update_todo(
            created.id,
            TodoUpdate(title="新标题", completed=True),
        )
        assert updated is not None
        assert updated.title == "新标题"
        assert updated.completed is True

    def test_update_todo_not_found(self, service):
        """测试更新不存在的任务应返回 None。"""
        result = service.update_todo(999, TodoUpdate(title="无"))
        assert result is None

    def test_delete_todo(self, service):
        """测试删除任务：删除后应无法再获取。"""
        created = service.create_todo(TodoCreate(title="待删除"))
        deleted = service.delete_todo(created.id)
        assert deleted is True
        assert service.get_todo(created.id) is None

    def test_delete_todo_not_found(self, service):
        """测试删除不存在的任务应返回 False。"""
        result = service.delete_todo(999)
        assert result is False


# ============================================================
# 集成测试 — FastAPI 路由
# ============================================================

@pytest.fixture
def client():
    """创建测试用的 AsyncClient，绑定到 FastAPI 应用。"""
    transport = ASGITransport(app=app)
    return AsyncClient(transport=transport, base_url="http://test")


@pytest.mark.asyncio
async def test_api_root(client):
    """测试根路径返回 API 信息。"""
    response = await client.get("/")
    assert response.status_code == 200
    data = response.json()
    assert "name" in data
    assert "version" in data


@pytest.mark.asyncio
async def test_api_create_todo(client):
    """测试 POST /api/todos 创建任务。"""
    response = await client.post("/api/todos", json={
        "title": "API 测试任务",
        "description": "通过 API 创建",
    })
    assert response.status_code == 201
    data = response.json()
    assert data["code"] == 201
    assert data["data"]["title"] == "API 测试任务"


@pytest.mark.asyncio
async def test_api_list_todos(client):
    """测试 GET /api/todos 获取任务列表。"""
    # 先创建一条数据
    await client.post("/api/todos", json={"title": "列表测试"})
    response = await client.get("/api/todos")
    assert response.status_code == 200
    data = response.json()
    assert data["code"] == 200
    assert data["total"] >= 1


@pytest.mark.asyncio
async def test_api_get_todo(client):
    """测试 GET /api/todos/{id} 获取单个任务。"""
    create_resp = await client.post("/api/todos", json={"title": "单个查询"})
    todo_id = create_resp.json()["data"]["id"]
    response = await client.get(f"/api/todos/{todo_id}")
    assert response.status_code == 200
    assert response.json()["data"]["title"] == "单个查询"


@pytest.mark.asyncio
async def test_api_get_todo_not_found(client):
    """测试 GET /api/todos/{id} 不存在的任务应返回 404。"""
    response = await client.get("/api/todos/99999")
    assert response.status_code == 404


@pytest.mark.asyncio
async def test_api_update_todo(client):
    """测试 PUT /api/todos/{id} 更新任务。"""
    create_resp = await client.post("/api/todos", json={"title": "待更新"})
    todo_id = create_resp.json()["data"]["id"]
    response = await client.put(f"/api/todos/{todo_id}", json={
        "title": "已更新",
        "completed": True,
    })
    assert response.status_code == 200
    assert response.json()["data"]["title"] == "已更新"
    assert response.json()["data"]["completed"] is True


@pytest.mark.asyncio
async def test_api_delete_todo(client):
    """测试 DELETE /api/todos/{id} 删除任务。"""
    create_resp = await client.post("/api/todos", json={"title": "待删除"})
    todo_id = create_resp.json()["data"]["id"]
    response = await client.delete(f"/api/todos/{todo_id}")
    assert response.status_code == 200
    # 再次查询应返回 404
    get_resp = await client.get(f"/api/todos/{todo_id}")
    assert get_resp.status_code == 404